From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Fri, 29 Apr 2022 12:22:10 -0400
Subject: [PATCH] SUNRPC: Ensure gss-proxy connects on setup
Git-commit: 892de36fd4a98fab3298d417c051d9099af5448d
Patch-mainline: v5.18-rc6
References: git-fixes

For reasons best known to the author, gss-proxy does not implement a
NULL procedure, and returns RPC_PROC_UNAVAIL. However we still want to
ensure that we connect to the service at setup time.
So add a quirk-flag specially for this case.

Fixes: 1d658336b05f ("SUNRPC: Add RPC based upcall mechanism for RPCGSS auth")
Cc: stable@vger.kernel.org
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 include/linux/sunrpc/clnt.h          |    1 +
 net/sunrpc/auth_gss/gss_rpc_upcall.c |    2 +-
 net/sunrpc/clnt.c                    |    3 +++
 3 files changed, 5 insertions(+), 1 deletion(-)

--- a/include/linux/sunrpc/clnt.h
+++ b/include/linux/sunrpc/clnt.h
@@ -142,6 +142,7 @@ struct rpc_add_xprt_test {
 #define RPC_CLNT_CREATE_INFINITE_SLOTS	(1UL << 7)
 #define RPC_CLNT_CREATE_NO_IDLE_TIMEOUT	(1UL << 8)
 #define RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT	(1UL << 9)
+#define RPC_CLNT_CREATE_IGNORE_NULL_UNAVAIL (1UL << 12)
 
 struct rpc_clnt *rpc_create(struct rpc_create_args *args);
 struct rpc_clnt	*rpc_bind_new_program(struct rpc_clnt *,
--- a/net/sunrpc/auth_gss/gss_rpc_upcall.c
+++ b/net/sunrpc/auth_gss/gss_rpc_upcall.c
@@ -110,7 +110,7 @@ static int gssp_rpc_create(struct net *n
 		 * timeout, which would result in reconnections being
 		 * done without the correct namespace:
 		 */
-		.flags		= RPC_CLNT_CREATE_NOPING |
+		.flags		= RPC_CLNT_CREATE_IGNORE_NULL_UNAVAIL |
 				  RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
 	};
 	struct rpc_clnt *clnt;
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -477,6 +477,9 @@ static struct rpc_clnt *rpc_create_xprt(
 
 	if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 		int err = rpc_ping(clnt);
+		if ((args->flags & RPC_CLNT_CREATE_IGNORE_NULL_UNAVAIL) &&
+		    err == -EOPNOTSUPP)
+			err = 0;
 		if (err != 0) {
 			rpc_shutdown_client(clnt);
 			return ERR_PTR(err);